so you're going to need to check a few things. You could turn on your headlights and turn the key to start and see if the headlights go dim at all. (a simple way to check for starter draw) If the lights don't dim then you need to see if you have a good battery voltage to the starter solenoid when the key is in the start position. Will need a test light for that. The headlights not dimming means that the starter is not drawing any power. bad starter, bad ignition circuit, bad battery connection.

If the lights do dim down then you have a high starter draw, Bad starter, seized engine (hydrostatic lock) With the key out of the ignition switch, use a socket and ratchet and see if you can manually turn the engine around.

you have to find out what is happening or not happening to figure where to begin on this one

so when you say it doesn't crank the motor after it turned for two seconds, does the starter stop making noise? so it's not like the bendix kicks out right? When you try to start again what happens? Not click or anything? Dash light all stay on like normal? Because a bad battery connection can go to open after you first crank and then the whole system can shut down.

no he means it dont crank over dont turn over cause the rear cylinders fill with gas and lock the engine up till the plugs are removed then it will kick the gas out and if ya put the plugs back in then it starts and runs rough till it eventually does it agian...... could it be timing slipped a tooth